Time-correcting device for electronic timepieces

ABSTRACT

An electronic timepiece is provided with a plurality of display elements for the digital display of time, driven by time-keeping circuitry. A time-correcting device coupled to said time-keeping circuitry is provided for independently correcting each of said display elements, said time-correcting device including a mechanical selector switch for selecting the display element to be corrected and a correction switch for performing the correction function on said display element.

Nishimura et al.

[ TIME-CORRECTING DEVICE FOR ELECTRONIC TIMEPIECES [75] Inventors: Izuhiko Nishimura; Toshiaki Ogata,

' both of Suwa, Japan [73] Assignee: Kabushiki Kaisha Suwa Seikosha,

Tokyo, Japan 22] Filed: Sept. 7, 1972 [21] Appl. No.: 287,202

[30] Foreign Application Priority Data 1 51 Dec. 24, 1974 3,699,763 10/1972 Zeph ..58/23R Primary Examine rEdith Simmons Jackmon Attorney, Agent, or FirmBlum, Moscovitz, Friedman & Kaplan 5 7 ABSTRACT An electronic timepiece is provided with a plurality of display elements for the digital display of time, driven Sept. 9, 1971 Japan 46-69297 by time-keeping circuitry. A time-correcting device coupled to said time-keeping circuitry is provided for [52] US. Cl. 58/23 R, 58/85.5 independently correcting each of said display ele- [51] Int. Cl....- G04c 3/00, G04b 27/00 ments, said time-correcting device including a me- Field Of rch 58/23 R, 50 85.5, 92 chanical selector switch for selecting the display ele- 35/ EA ment to be corrected and a'correction switch for per-' 1 forming the correction function on said display ele- [56] References Cited ment.

UNITED STATES PATENTS 3,576,099 4/1971 Walton 58/23 R 6 Claims, 7 Drawing Figures a 30 3 29 Z8 MEK/M/V/(Wl 6' LECTl/VG DEV/CE V DIV/0H5 l l j DECODER, 0mm? mvo 0/5/2221 Y C/RCUUS PATENTEB M824 1974 SHEET 2 95 g PATENIED M $855,782

sum u 4 TIME-CORRECTING DEVICE FOR ELECTRONIC TIMEPIECES BACKGROUND OF THE INVENTION This invention relates to devices for correcting the digital display of electronic timepieces. Such digital displays generally consist of a plurality of digits representative of the hours, minutes, and seconds time indication. In the art, a pushbutton correction switch has been provided for each of said time display digits, occupying a great deal of space in the watch case, and causing confusion and difficulties in operation. By providing a mechanical selector switch for selecting the digit to be corrected these difficulties have been avoided.

SUMMARY OF THE INVENTION Generally speaking, in accordance with the invention, an electronic timepiece is provided including timekeeping circuit means and display means. Said display means is provided with a plurality ofdigits for the display of time. Said timekeeping circuit means includes a frequency divider stage operatively coupled to each digit of said display means for providing timing signals for the driving of said display means digit. A time-correction means is operatively coupled to at least two of said divider stages, said time-correction means including a selector switch for selecting one or more of said two or more divider stages to be corrected and an enabling switch for applying a time-correcting signal to the selected detector stage. Said selector switch may take the form of a rotary switch or a slide switch.

Accordingly, it is an object of the invention to provide an accurate and quick means for performing the time-correction function in an electronic watch.

Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.

The invention accordingly comprises the features of construction, combinations of elements, and arrangement of parts which will be exemplified in the constructions hereinafter set forth, and the scope of the invention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompanying drawings, in which:

FIG. 1 is a block diagram of an electronic timepiece including a conventional time-correcting device;

FIG. 2 is a top plan view of a display segment for displaying a single digit in the digital display of FIG. 1;

FIG. 3 is a circuit diagram of a decimal counter circuit, a decoder circuit and a driver circuit for the electronic watch of FIG. 1;

FIG. 4 is a graphical representation of the relation between voltage applied to a liquid crystal material and the light-scattering effects produced therein;

FIG. 5 is a block diagram of an electronic timepiece incorporating the time-correcting device in accordance with the invention; and

FIGS. 60 and 6b are perspective views of two embodiments of the mechanical selector switch in accordance with the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIG. 1, the electronic timepiece depicted includes an electronic frequency standard oscillator OSC of high precision which produces a highfrequency time standard signal which is applied to a frequency divider circuit I. Said frequency divider circuit consists of a series of flip-flop stages and reduces the highJrequency time standard signal to a signal having a pulse once every second. This one second signal is applied to a decimal divider circuit 2 which produces a pulse signal every ten seconds. Said ten-second signal is applied to a one-sixth divider circuit 3 which produces a pulse signal every minute. This one-minute signal is applied to a decimal divider circuit 4 which produces a pulse signal every ten minutes. This ten-minute signal is applied to a one-sixth divider circuit 5 which produces a pulse signal every hour. Said one-hour signal is applied to a decimal divider circuit 6 which produces a pulse signal every ten hours. The ten-hour signal is applied to a divider circuit 7 which serves to recycle the divider chain at the end of each 24-hour period.

Divider stages 2, 3, 4, 5, 6 and 7, respectively, drive display elements 8-l, 8-2, 8-3, 8-4, 8-5 and 8-6 of the digital display device. The one-second digit is displayed on display element 8-1, the ten-second digit is displayed on display element 8-2, the one-minute digit is displayed on display element 8-3, the ten-minute digit is displayed on display element 8-4, the one-hour digit is displayed on display element 8-5, and the ten-hour digit is displayed on display element 8-6.

Each display element is formed from a sevensegment array in the nature of a seven-bar display, as depicted in FIG. 2. By selective actuation of the seven bars L L,,, L L L L, and L, of the display, any numeral from 0 to 9 may be displayed digitally. In'FlG. 2, the cross-hatching represents the segments or bars actuated to display the numeral 2. Each display segment may be formed from luminous diodes, liquid crystal material or the like.

Theoutput of each divider stage 2-7 would be applied to decoder and driver circuits as more particularly depicted in the circuit diagram of FIG. 3. In said circuit diagram, a decimal divider circuit 201, corresponding by way of example to divider circuit 2, is depicted. Said divider circuit consists of four flip-flop circuits FF FF FF FF Each of the flip-flop circuits is of the data type and operates at O, D O where D and O are connected together and i-l represents the condition one digit before the condition at 1'. An AND circuit 205 receives signals from selected terminals of each of the flip-flops such that said flip-flops are reset when flip-flops FF FF FF and FF are disposed respectively in the 1,0,1 ,0 state (representative of a decimal 10), thereby producing a decimal counter. The other divider stages are constructed in accordance with the same principles.

The decoder circuit 202 is adapted to select the segments of the associated display elements representative of the state of the flip-flops of divider 201. Driver circuit 203 applies decoded driving signals to the selected segments 204. Counter circuit 202 consists of eight OR gates 206 and six AND gates 207. The drive circuit when an element is not to be displayed and a voltage V when a segment is to be displayed. Since the segments of the display 204 are formed from a liquid crystal material in the embodiment depicted in FIG. 3, this voltage below a fixed level. This characteristic is illustrated in the graph of light-scattering vs. voltage of FIG. 4. The continuous application of a minimum voltage below the threshold of light-scattering hastens the re sponse speed of the liquid crystal display cells. Each display segment is connected between a voltage V and one of the MOS transistor switches.

Referring again to FIG. 1, the conventional timecorrecting device depicted consists of a plurality of switches SW SW SW SW SW,, and SW each of which is connected on one side to a common terminal 11 and on the other side to one of divider stages 2, 3, 4, 5, 6 and 7. The correcting signal is applied to tenninal 11 for application to the'selected one of the divider stages for correcting same. Where six digits were to be corrected, six separate switches, usually of the pushbutton type, were provided, increasing the size of the wristwatch, and making time correction both difficult and subject to error.

An electronic water incorporating a time-correcting device in accordance with the invention is depicted in which corresponds in function and structure to the oscillator OSC and divider chain 1, 2, 3, 4, 5, 6 and 7 of FIG. 1. Similarly, the watch is provided with decoding, driving and display circuits 27-1, 27-2, 27-3, 27-4, 27-5 and 27-6, which correspond in structure and function to the decoder, driving and display circuits 8-1, 8-2, 8-3, 8-4, 8-5 and 8-6 of FIG. 1. The correcting signal at terminal 31 is selectively applied through a common switch 30 and a selecting switch 32 to each of divider stages 21, 22, 23, 24, 25 and 26. Selecting switch 32 is manually operable as indicated schematically by terminal 29 to selectwhich one of the divider stages is to be corrected. Both switches 30 and 32 project outside the watch case and are manually manipulatable.

A reset signal is applied from terminal 28 to each of the divider stages 20, 21, 22, 23, 24, 25 and 26 for return-to-zero of each of said divider stages in the same manner that a reset signal may be applied to terminal 9 0f FIG.,1.

Referring now to FIG. 6a, one embodiment of a mechanical selecting switch in accordance with the invention is depicted. This mechanical selecting switch is provided with a plurality of fixed contacts P, two of which are depicted in FIG. 6a, such fixed contacts being circumferentially spaced in the path of a movable contact R mounted on a rotor operable from outside of the watch case. The correcting signal would be applied by second manually operated switch 30 of FIG. 5, to the fixed contact R along lead 0. Each fixed contact P would be connected to one of divider stages 21-26 of FIG. 5.

The second embodiment of the selecting switch is depicted in FIG. 6b, said second embodiment being based on a slide switch having a holdfast feature. Said switch consists of slider plates S, and S which are joined as a single body by connecting them with C3,. This body slides from side to side along guide plates 0,, G which also serve as the watch case. A contact plate C is mounted on rear slider plate 8,; through a connecting member CB Contact plate C is provided with'a notch N in the upper surface thereof for engagement with spring contact elements T T The number of these spring contacts will depend on the number of digits of the display device to be corrected, one of said contacts being provided for each digit. The resilient property of the spring contacts T T permits engagement in the notch N for retaining the slide at each operative position. The outer surface of guide plate G, is provided with marks lVl M etc. corresponding in position to each of said spring contacts providing a marker for the user in positioning the slide. The correcting signal would be applied to the movable contact C,,. The embodiment of FIG. 6b defines a click-stop selecting switch which may readily be incorporated in a wristwatch. By the provision of an additional manually operated switch corresponding to switch 30 of FIG. 5, either the arrangement of FIG. 6a or the arrangement of FIG. 6b defines a manually operable time-correcting device which is readily usable through the manipulation of a minimum number of switches.

It will thus be seen that the objects set forth above, among those made apparent from thepreceding description, are efficiently attained, and since certain changes may be made in the above constructions without departing from the. spirit and scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

What is claimed is:

1. An electronic timepiece comprising oscillator circuit means for producing a high-frequency time standard signal; multi-stage frequency divider circuit means for sequentially dividing said high-frequency time standard signal and producing low-frequency timekeeping signals at a selected group of said stages; display means including a plurality of display elements for the digital display of time; means for driving each of said display elements in response to one of said timekeeping signals; and time-correcting means including a manually operable selector switch means connected to at least two of the divider stages producing said timekeeping signals for selecting one of said divider stages, and a secondary switch means manually operable independent of said selector switch means for selectively applying a timecorrection signal through said selector switch means to the selected divider stage for correcting the display element associated with said selected divider stage.

2. An electronic timepiece as recited in claim 1,

wherein said selector switch is a rotary switch.'

3. An electronic timepiece as recited in claim 1, wherein said selector switch is a slide switch.

4. An electronic timepiece as recited in claim 3, including a watch case, said watch case being formed with a longitudinally extending slot; said selector switch means including a slide member mounted on said watch case for longitudinal displacement along said slot in response to manual manipulation by the user; said movable contact being mounted on said slide member,

said movable contact is'in registration therewith.

6. An electronic timepiece as recited in claim 1, wherein said selector switch means is coupled to each of the divider stages producing said timekeeping signals. 

1. An electronic timepiece comprising oscillator circuit means for producing a high-frequency time standard signal; multi-stage frequency divider circuit means for sequentially dividing said high-frequency time standard signal and producing low-frequency timekeeping signals at a selected group of said stages; display means including a plurality of display elements for the digital display of time; means for driving each of said display elements in response to one of said timekeeping signals; and timecorrecting means including a manually operable selector switch means connected to at least two of the divider stages producing said timekeeping signals for selecting one of said divider stages, and a secondary switch means manually operable independent of said selector switch means for selectively applying a time-correction signal through said selector switch means to the selected divider stage for correcting the display element associated with said selected divider stage.
 2. An electronic timepiece as recited in claim 1, wherein said selector switch is a rotary switch.
 3. An electronic timepiece as recited in claim 1, wherein said selector switch is a slide switch.
 4. An electronic timepiece as recited in claim 3, including a watch case, said watch case being formed with a longitudinally extending slot; said selector switch means including a slide member mounted on said watch case for longitudinal displacement along said slot in response to manual manipulation by the user; said movable contact being mounted on said slide member, said fixed contacts being positioned in the path of said movable contact.
 5. An electronic timepiece as recited in claim 4, wherein said movable contact is formed with a notch in the path of said fixed contacts, said fixed contacts being resiliently mounted for engagement in said notch when said movable contact is in registration therewith.
 6. An electronic timepiece as recited in claim 1, wherein said selector switch means is coupled to each of the divider stages producing said timekeeping signals. 